Cosmic Rays

Abstract

The space above the atmosphere of the earth — between the planets and the stars — is thought by many people only to be empty space. Yet it contains and is traversed by an immense diversity of radiation, both electromagnetic and nuclear. Occasional dust particles are also present. The radiation carries information about distant bodies in the cosmos, and its complexity delivers elaborate clues to the nature of astrophysical processes that have emitted vast quantities of energy. Examples of these sources are the surface of our sun, supernova explosions, pulsars, and red giant stars.